The present invention relates to cooling systems wherein a sorbate is alternately adsorbed onto and desorbed from a sorbent. More particularly, the invention relates to an improved sorber structure which may be flexible or which may form a structural component of a corresponding sorption system.
In adsorption and absorption systems, which will be referred to herein as sorption systems, a first substance called a sorbate is alternately adsorbed (or absorbed) onto and then desorbed from a second substance called a sorbent. Specific sorbates and sorbents will usually be selected for a particular sorption system to produce a desired effect which is dependent on the affinity of the two substances. During an adsorption reaction, which is also referred to as the adsorb cycle or the adsorb portion of the sorption cycle, the sorbate is drawn onto and combines with the sorbate to produce a sorbate/sorbent complex, which will be referred to herein simply as a sorbate/sorbent compound. During the desorption reaction, which is also called the desorb cycle or the desorb portion of the sorption cycle, energy is supplied to the sorbate/sorbent compound to break the bonds between the sorbate and sorbent molecules and thereby desorb, or in other words separate or drive off, the sorbate from the sorbent. Substantial energy is imparted to the sorbate during the desorption reaction, and this energy can be harnessed for various uses.
An exemplary refrigeration sorption system may use a polar refrigerant, such as ammonia, as the sorbate and a metal halide salt, such as strontium bromide, as the sorbent. During the desorption reaction, which occurs in an enclosure called a sorber, the refrigerant molecules are driven off of the salt and into a relatively high pressure, high energy gaseous state. The refrigerant gas is subsequently condensed and then evaporated to produce a cooling effect. The evaporated refrigerant gas is then channeled back to the sorber, where it is once again adsorbed onto the salt in an adsorption reaction. The sorption cycle is repeated numerous times depending on the cooling requirements of the refrigeration system.
In certain prior art sorption systems, the desorption energy is supplied by a conventional heater. In such a system, a great deal of thermal energy is required to stochastically heat the sorbate/sorbent compound to the degree sufficient to break the bonds between the sorbate and sorbent molecules. As a result, the sorbate, sorbent and sorber are significantly heated, and substantial time and/or energy are required to remove this sensible heat and cool the sorber and sorbent before the next adsorption reaction can proceed.
In the refrigeration system described in the above-mentioned application, the desorption energy is supplied in the form of electromagnetic waves, such as radio frequency waves or microwaves, generated by, for example, a magnetron. Instead of heating the sorbate/sorbent compound, the electromagnetic waves selectively pump electrical energy into each sorbate-sorbent bond until the bond is broken and the sorbate molecule is separated from the sorbent molecule. Therefore, the sorbate, sorbent and sorber are not heated during the desorption reaction and consequently do not need to be cooled before the next adsorption reaction can proceed. As the desorption reaction is essentially isothermal, the overall performance of the refrigeration system is greatly improved.
It has been discovered that the efficiency and speed of the desorption reaction in an electromagnetic wave-activated sorption system can be increased by uniformly transmitting the electromagnetic waves to the entire volume of sorbate/sorbent compound contained within the sorber.
According to present invention, a sorber for use in a sorption cooling system is provided, wherein the sorber has a housing which is adaptable to a variety of physical configurations. In one embodiment of the invention, the sorber comprises a flexible enclosure having an outer conductor, and inner conductor, a port through which a sorbate can be communicated into and out of said enclosure, and a sorbent in the enclosure which can adsorb the sorbate to form a sorbate/sorbent compound. The enclosure is configured to be coupled to an electromagnetic wave generator so that waves generated by the electromagnetic wave generator propagate through the sorbate/sorbent compound within the enclosure. The sorber enclosure may be coiled or otherwise bent. In some embodiments, the sorber enclosure may be configured to serve as a structural component of the sorption cooling system.
These and other objects and advantages of the present invention will be made apparent from the following detailed description, with reference to the accompanying drawings.